docs: def supports(cls, *functionalities):
          """
          A view decorator to indicate that an xBlock view has support for the
          given functionalities.
  
          Arguments:
              functionalities: String identifiers for the functionalities of the view.
                  For example: "multi_device".
          """
          def _decorator(view):
              """
              Internal decorator that updates the given view's list of supported
              functionalities.
              """
              # pylint: disable=protected-access
              if not hasattr(view, "_supports"):
                  view._supports = set()
              for functionality in functionalities:
                  view._supports.add(functionality)
              return view
          return _decorator